1. Technical Field
The present disclosure relates to a biochip and a fabrication method thereof, and more particularly, to a biochip including a side emitting-type light-emitting device, in which light emitted from the sides of the light-emitting device included in a bio-layer can cause a biochemical reaction, and which can detect light emitted by the biochemical reaction to thereby provide biochemical information, and to a method for fabricating the biochip.
2. Related Art
In general, a biochip is formed by arraying reference samples including biological molecules such as DNA and proteins on a substrate made of a material such as glass, silicon, a metal such as gold, or nylon.
The biochip basically uses biochemical reactions between the reference sample fixed to the substrate and a target material. Representative examples of the biochemical reaction between the reference sample and the target sample include the complementary binding of DNA bases, and an antigen-antibody reaction.
Diagnoses using the biochip are generally performed by detecting the degree of a biochemical reaction between the reference sample and the target sample through an optical process. An optical process that is generally used is based on fluorescence or luminescence.
FIG. 1 shows a cross-sectional view of a conventional chip having an image sensor.
Referring to FIG. 1, a biochip 100 having an image sensor comprises a bio-layer 110, a filter layer 120 and an image sensor layer 130.
The bio-layer 110 is a layer in which a biochemical reaction between a reference sample and a target sample takes place. In addition, as a result of the biochemical reaction, a luminescent or fluorescent material remains in the bio-layer 110.
In the case in which a luminescent material remains in the bio-layer 110, it is required to block external light, because the luminescent material itself emits light. However, in the case in which a fluorescent material remains in the bio-layer 110, separate external light is required to emit light from the fluorescent material. Thus, in this case, a filter layer is required to block the external light from being incident to the image sensor layer.
The filter layer 120 is formed under the bio-layer 110. The filter layer functions to block the external light from being incident to the image sensor layer disposed under the filter layer, when a fluorescent material remains as a result of the biochemical reaction.
In other words, the external light acts as noise in a process of measuring the fluorescence of the fluorescent material by the image sensor layer. Thus, the filter layer functions to remove the external light that is noise.
The image sensor layer 130 is formed under the filter layer 120, and comprises a plurality of photodetectors 131. The plurality of photodetectors 131 functions to detect the light filtered by the filter layer and to convert the detected light into an electrical signal.
However, the conventional biochip 100 as described above has shortcomings in that the difference between the wavelength (λ1) of the external light and the wavelength (λ2) of light emitted from the luminescent or fluorescent material is very small and in that it is required to design a precise filter layer 120 capable of filtering out light corresponding to this small difference.